From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Technical report evaluating various electrical components including lamps, switches, and horns.
| Identifier | ExFiles\Box 168a\4\ img079 | |
| Date | 11th May 1938 | |
| -2- Rm{William Robotham - Chief Engineer}/RCll/S.11.5.38. Head Lamps. LOP. DW.184. These lamps were fitted with a 7 lb reflector spring and improved rubber sealing rings. Apart from a criticism that 60 watt bulbs, used in them, were too powerful, they were found to be quite satisfactory. Fog Lamp. This lamp, one of the Lucas PF 57 type, was criticised on the grounds that when used as a pass light, there was a tendency to dazzle. It was considered to be inferior to the FT 67 type (also tested in this car) in all respects. Dipper Switch; LOP. DW.154. When examined, the toggle spring was missing: otherwise the switch was found to be in a good condition. Stop Lamp Switch. LOP.DW.236. One of the spring contacts was found to be worn right through. The small hole made, suggested that the wearing surface was not large enough. Petrol Pump Switch (Lucas). The condition of this unit was good. Instrument Group. This was made to R.R. scheme 1110. It was considered satisfactory apart from the fact that four of the 3 1/2 volt bulbs burnt out during the test. The life of this 3 1/2 volt bulb was, apparently, short; due to too high a working voltage, or poor manufacture. This is being investigated. Horns & Relay. LOP. DW.184. (Lamp Horns & Fittings). The horns were of the experimental WT.13 type, they were again considered to be more effective than the present standard horns, and should, therefore, go forward for standardisation. It was reported that during the run, two of the securing screws worked loose, one on one of the horns, and allowed the trumpet to fall off. Also, one of the horns got out of adjustment and failed. When tested on the bench, this one failed to sound on the soft side but was quite O.K. on the loud side. The question of locking the securing screws, apart from the taper on the countersunk heads, should again be taken up with the makers. We previously criticised this point, but were assured by the makers that the taper provided an efficient locking device. | ||